This invention relates to the combination of a valve and a connector for that valve, referred to as a flanged valve connector, for connecting metallic or non-metallic pipe directly to the valve body.
In the pipeline industry there has been a significant renewal of pipe particularly in gas transmission and distribution pipeline systems. In distribution systems cast iron and steel pipe is being replaced by plastic pipe. This replacement poses problems both in the tie-in connection of the plastic pipe to the metallic pipe as well as in the installation of valves in the renewed pipeline. Where plastic pipe is connected to metallic pipe the connection may be with a mechanical bolt type coupling or with a special steel-to-plastic pipe transition fitting which is welded directly to both the steel and plastic piping.
If a steel valve was necessary at the tie-in connection or elsewhere in a plastic pipeline, it was necessary prior to this invention, to use a stub end valve and to first extend the stub end by welding a short length of steel pipe, or what is known as a "pup", to each end. This was done in order for the valve ends to accept the installation of mechanical bolt-on type couplings. The valve was then installed into the pipeline by connecting one extended stub end to the metallic pipe with a metallic bolt-on type coupling and connecting the opposite extended stub end to the plastic pipeline with a mechanical bolt-on type coupling. An alternative valve installation used when steel pipe and plastic pipe were involved, is to use a stub end valve and to weld one stub end directly to the steel pipeline and to weld the special steel-to-plastic transition fitting to the opposite valve stub end and then to weld the fitting to the plastic pipeline. So far as is known, there has not been provided a valve structure which would solve this problem of connecting pipelines of dissimilar or incompatible material and also act to provide valving for the line.
My invention overcomes the aforementioned problems by providing a valve and connector structure which may be attached to the free end of a plastic pipeline or a metallic pipleine to both seal and hold the plastic or metallic pipe to the valve body, and also to allow the other side of the valve to be welded to a metallic pipeline in the usual fashion.